ARLINGTON NATIONAL CEMETERY, Va. - Nearly a half century ago, Americans witnessed a late November darkness that was eventually illuminated by an eternal flame.

On Oct. 29, that flame at the John F. Kennedy gravesite in Arlington National Cemetery was transferred from temporary to permanent status by Secretary of the Army John McHugh and the cemetery's Chief Engineer and Acting Chief of Staff Army Col. Michelle Stewart.

The temporary flame has been used at the JFK burial site since April so construction upgrades could be performed. The U.S. Army Corps of Engineers Norfolk District and construction partners combined to finish a number of tasks before the assassination anniversary. The project replaced the burner assembly and the supporting infrastructure including gas, electric and compressed air lines for the flame as well as installed new drainage lines below the flame. Workers also relocated gas pressure regulators from inside to outside the chamber to provide easier maintenance and access.

"An upgrade such as this can be challenging for any project, but even more so for such an iconic symbol that remained so visible to the public during construction," Army National Military Cemeteries and Arlington National Cemetery Executive Director Patrick K. Hallinan told a gathered crowd of several hundred during the 20-minute ceremony.

He called the transfer "an historic event" and explained that millions of service members and tourists from around the world have traveled to Arlington to pay respect to the 35th president of the United States and his family at the Cape Cod fieldstone grave, which is highlighted by a five-foot circular flat-granite stone that rests below the re-transferred perpetual flame.

"And they come to see the eternal flame," the executive director said. "[It is] the embodiment of hope and renewal - a symbol that is just as relevant today as it was then."

The Oct. 29 ceremony ended a period which marked only the second time a temporary flame has been used at the grave. The first time was when First Lady Jacqueline Kennedy lit a temporary flame during the Nov. 25, 1963 burial following her husband's Nov. 22 assassination. That flame was then transferred to the permanent eternal flame in March 1967.

"As we approach the 50th anniversary of President Kennedy's death, it is fitting that we once again transfer the flame from a temporary one to a permanent eternal flame - a flame that is more modern, more efficient and ensuring the light continues to remain a beacon of hope and remembrance for all who see it," Hallinan added.

The transfer ceremony starts a string of JFK remembrance events that will take place at Arlington National Cemetery. Starting Nov. 15, a special pictorial exhibit honoring President Kennedy's legacy will be on display in the basement of the Memorial Amphitheater. This exhibit will be on display through Dec. 1, 2013. On Nov. 22, Arlington National Cemetery will conduct a wreath-laying remembrance ceremony at President Kennedy's gravesite. On the 50th anniversary of the funeral, the Irish Defence Forces 37th Cadet Class will conduct a remembrance ceremony at President Kennedy's gravesite. The 37th Cadet Class flew to Washington to provide an honor guard during the 1963 Kennedy funeral service.